m_axis Interface - 2022.2 English

Vitis Networking P4 User Guide (UG1308)

Document ID
UG1308
Version
2022.2 English
Revision

The following table shows the breakdown of the m_axis interface signals.

Table 1. m_axis Interface
Name I/O Description
m_axis_tdata O Packet data bus of configurable width.
m_axis_tvalid O Indicates that the master is driving a valid transfer. A transfer takes place when both m_axis_tvalid and m_axis_tready are asserted.
m_axis_tkeep O Indicates whether the content of the associated byte of s_axis_tdata is processed as part of the data stream. For metadata output of dropped packets, m_axi_tkeep = 0. This is described in the User Metadata Interface section.

Note: There no are invalid byte gaps in the middle of the data bus.
m_axis_tlast O Indicates the boundary of the packet.
m_axis_tuser O User-defined sideband information transmitted alongside the data stream. It is only present if the axis_tuser keyword appears as a field name within the user metadata structure of a P4 program. It is valid beginning with the first word of an outgoing packet from the Vitis Networking P4 IP. The field remains at the same value for the duration of each packet.
m_axis_tdest O Provides routing information for the data stream. It is only present if the axis_tdest keyword appears as a field name within the user metadata structure of a P4 program. It is valid beginning with the first word of an outgoing packet from the Vitis Networking P4 IP. The field remains at the same value for the duration of each packet.
m_axis_tid O Data stream identifier that indicates different streams of data. It is only present if the axis_tid keyword appears as a field name within the user metadata structure of a P4 program. It is valid beginning with the first word of an outgoing packet from the Vitis Networking P4 IP. The field remains at the same value for the duration of each packet.
m_axis_tready I Indicates that the slave can accept a transfer in the current cycle.